The First Symposium of Subtypes of Muscarinic Receptors, held in 1983, was the first to probe a field ignored for years by all but a few investigators. As a result of research directed at a practical problem of therapeutics, the concept of subtypes of the muscarinic receptor became a reality and a whole field of research was energized into rapid growth. In the short time since the first symposium 3 subtypes have been clearly defined on the basis of new and selective antagonists and the sequences, distribution, and coupling mechanisms of 5 muscarinic receptors disclosed. The Eighth Symposium will continue the precedents set previously by increasing our basic knowledge of muscarinic receptors and disclosing new agonists and antagonists of potential or demonstrated therapeutic value. The major goals are to provide a forum for interaction between individuals who are actively studying muscarinic receptor function and investigators who are actively pursuing the identity and structure of receptor subtypes with technologies evolved from molecular cloning. The broad areas to be covered include: 1) molecular pharmacology and physiology of muscarinic receptors and interactions with other systems; 2) development, medicinal chemistry and clinical aspects of new, selective agents, particularly, with respect to genito-urinary systems, and cardiovascular and pulmonary function, and 3) new insights into the role of muscarinic receptors in the central nervous system and their revilance to Alzheimer's Disease and senile dementia. This symposium provides a unique opportunity for interaction between biochemists, physiologists, pharmacologists and neuroscientists who are the leaders in the multidisciplinary approach being taken in the field and young investigators and predoctoral fellows who will present their work in the poster sessions.